Robust Bismuth Nanoscrolls for High-Rate and Durable Sodium-Ion Batteries

Bismuth-based alloying materials have emerged as highly promising anodes for sodium-ion batteries (SIBs) due to their high theoretical specific capacity, superior volumetric capacity, and suitable operating voltage; however, substantial volume variation during alloying/dealloying and sluggish reaction kinetics critically compromise their cycling stability. To simultaneously address these challenges, this study designed and engineered a unique bismuth nanoscroll (BNR) structure derived from self-assembled nanosheet scrolling. This architecture substantially enlarges the electrochemically active surface area relative to commercial bismuth powder, thereby facilitating efficient reversible Na + intercalation/deintercalation. Consequently, the BNR anode delivers exceptional sodium storage performance: it achieves a remarkable 99.71% capacity retention after 900 cycles at 1A g −1 and demonstrates ultra-long cycling stability for 2500 cycles even at a high rate of 2 A g −1 . Furthermore, a full cell configured with the BNR anode paired with a Na 3 V 2 (PO 4 ) 3 (NVP) cathode maintains a stable capacity of 243.27 mAh g −1 following 250 cycles at 0.1 A g −1 . Beyond introducing a novel synthesis strategy for high-performance bismuth nanowires that exhibit exceptional cyclability in SIBs, this work provides pivotal insights for developing advanced electrode materials targeting high-energy-density and long-cycle-life sodium-ion batteries. Graphical This article investigates the structure–property relationship of spherically compact bismuth nanoscrolls (BNR) for sodium-ion battery anodes. Bismuth has emerged as a promising anode material due to its high volumetric capacity and stable alloying mechanism. The study reveals that the unique spherical architecture, self-assembled from numerous nanoscrolls, enables high performance and long cycle life in sodium-ion batteries through the synergistic effect of accelerated ion transport via one-dimensional channels and effective strain buffering within the internal space.